1. Field of the Invention
The invention relates to a semiconductor imaging instrument which is suitably applied to, for example, a digital camera provided with a solid-state imaging device or a field effect imaging device each having light receiving sensitivity to not only visible light but also infrared light and a manufacturing method thereof, and to a camera and a manufacturing method thereof. In detail, by providing a color filter layer containing an infrared light absorbing dye on an imaging device array having plural semiconductor imaging devices and electrodes, the invention is able to realize an infrared light cutting function by this color filter layer and to provide low transmissibility of infrared light as required for an infrared light cutting function in addition to high transmissibility of visible light as required for a color filter function.
2. Description of the Related Art
In recent years, video cameras and digital still cameras have been frequently used in schools, homes, broadcasting stations, and so on. In cameras of such a kind, a semiconductor imaging instrument is indispensable. In the semiconductor imaging instrument, in a solid-state imaging device or a field effect imaging device, CCD (charge coupled device) imaging devices as a photoelectric conversion device are two-dimensionally arranged, and light is introduced into the charge coupling device by a microlens or the like. The “CCD imaging device” as referred to herein means a semiconductor device having a structure in which unit devices made of a photodiode, an MOS capacitor, etc. are regularly arranged. The semiconductor imaging instrument has a function to move a certain group of charges as stored on a surface of a semiconductor substrate along the line of electrodes of the MOS capacitor.
A solid-state imaging device of this kind, for example, CCD and CMOS image sensors has sensitivity in an infrared light region. In a camera using this solid-state imaging device, in many cases, a filter for cutting infrared light is mounted on a camera optical system for the purpose of precisely separating the color.
Recently, miniaturization of a digital camera has been advancing. However, since the filter for cutting infrared light has a thickness of from approximately 1 to 3 mm, the thickness of the filter is of a problem in view of thinning the digital camera. In particular, in a camera module to be mounted in a mobile phone handset, a portable terminal, or the like, thinning of the optical system is essential.
In relation to such a filter for cutting infrared light, JP-A-2004-200360 (Patent Document 1) discloses a solid-state imaging device and a manufacturing method thereof. According to this manufacturing method of a solid-state imaging device, a microlens provided with an infrared light absorbing function and a flattening layer are formed on a photoelectric conversion device formed on a desired substrate. It is said that by employing such a manufacturing method, an external filter for cutting infrared light becomes unnecessary; that the condensing properties can be improved; that an S/N ratio can be improved; and that the image quality can be enhanced.